Sensory Evaluation of Ice cream

Ice cream is a highly popular frozen dairy product and liked by persons of all age group. Hence, several varieties of ice cream are available in market. Here we are discussing the sensory evaluation of plain/vanilla ice cream.

i. Desirable Attributes of Ice Cream

a) Colour: The colour should be attractive, uniform, pleasing and typical of the flavour present in ice cream. Vanilla ice cream is invariably plain (no colour).The colour defects of ice cream are grey/dull; non-uniform, vivid and unnatural.

b) Package: The package or container should be neat, clean, attractive, full and protective. The common package defects are: soiled, rusty, damaged, shrunken ice cream, ill shaped, etc.

c) Melting quality: Good quality ice cream should show little resistance towards melting when a dish is exposed to room temperature. During melting, the mix should drain away as rapidly as it melts and form a smooth, uniform and homogenous liquid in the dish. Any variation from this behaviour is due to some defect and leads the consumers to be suspicious of its quality. Though the weightage to the melting quality is low (5 points), it is an important attribute on account of its correlation with the body and texture.

d) Body and Texture: The desired body in the ice cream is firm, has resistance, responds rapidly to dipping and melts down at ordinary temperature to a creamy consistency. The desired texture should be fine, smooth, velvety and carries the appearance of creaminess throughout.

e) Flavour: Vanilla ice cream should be pleasantly sweet, having a creamy, delicate bouquet vanilla flavour that cleans up well, leaving only a very pleasant aftertaste.

ii. Score Card of Ice cream

The following score card based on 100 points is used for judging ice cream(Table)

Score Card for Ice Cream

In general practice, the item of bacteria is not done along with judging and the perfect score of 15 is allowed.

iii. Scoring Technique of Ice Cream

i) Tempering of ice cream: Ice cream starts melting immediately after removing from hardening room. Arrangement should, therefore, be made to hold the ice cream at a uniformly low temperature so that its true body & texture characteristics can be perceived. The temperature of judging, however, should not be so low that ice cream is intensely cold and very hard. Also, its evaluation at very low temperature temporary nimbs the taste senses that take long time for recovery to normal condition. Generally, temperature in range of –15oC to –12.2oC is satisfactory for tempering the ice cream for sensory evaluation. To achieve, this ice cream should be taken out from the hardening room and placed in dispensing cabinet several hours prior to judging. In this way, ice cream tempers uniformly.

ii) Sampling: The retail package of ice cream should be served as such for judging.In case of a large lot or bulk, a regular ice cream dipper or scoop is used for drawing the sample. The sample for melt down need not be large but must be uniform in size among the various lots of ice cream being judged. For this, a certain quantity of ice cream is kept in a clean petri-dish and melting qualities should be observed from time to time during scoring. The samples from large lots can be placed in separate plates or all in one large service plate. For taking a sample into the mouth a metal spoon is better than a wooden spoon.

iii) The condition of ice cream starts changing immediately after taking it out of the cold store. Therefore, the judging and scoring of ice cream should be very fast. The judges should record their observations as quickly as possible, particularly about the body and texture characteristics. The observations should be made in the following sequence:

a) Examine the container for cleanliness, fullness, printing defects, etc.

b) Note the colour of ice cream for its intensity and uniformity.

c) While sampling with a dipper/scoop or spoon, note the way the product cuts and the feel of the dipper as its cutting edges pass through the frozen mass. Note particularly whether the ice cream tends to curl up or roll in serrated layers behind the dipper thus indicating excessive gumminess or stickiness. The feel of “dipping”, that is, the resistance offered, the evenness of cutting, the presence of spiny particles and whether the ice cream is heavy and soggy, or light and fluffy, should be carefully observed.

d) Unless the ice cream has been melted and mix warmed, it is so cold that for all practical purposes any odoriferous substances present are practically non-volatile and, therefore, little or no aroma may be detected. During the judging of ice cream, taste reactions (such as sweet, salty, sour or bitter) are perceived earlier than odour. Therefore, place a little sample directly into the mouth for warming and liquefying it. While manipulating the sample between the teeth and the palate, note the taste and odour sensations.The texture characteristics, such as gumminess, grittiness, coarseness, sandiness, etc. should also be felt simultaneously.

e) Note the melting qualities of ice cream. The judges should observe whether the ice cream has retained its form and appropriate size, even though some free liquid may have oozed out, whether the melted liquid is creamy curdled, foamy, watery, and whether the tiny channels are formed as the melt drain flow down the sides of mass.

iv. Undesirable Attributes of Ice Cream

The defects related to colour and package have been given earlier and those of melting behaviour, body & texture and flavour are mentioned as below:

Melting quality: Does not melt or delayed melting, flaky or scummy, foamy or frothy, wheying off or curdled and watery.

Body and texture: Crumbly (brittle/flaky/snowy), gummy (pasty/sticky), shrunken, soggy (heavy/doughy), weak, buttery/greasy, coarse (grainy/ icy/spiny), fluffy and sandy.

Off flavours: Cooked, sour, old ingredients, rancid, salty, inadequate or excessive flavour, oxidized/tallowy, neutralizer, etc.